The present invention relates to a novel closure assembly for vehicles such as automobiles, and more particularly to vehicle aperture closure assemblies such as multi-part doors and displaceable roof sections for apertures formed in a generally curved exterior wall.
Automotive vehicles are typically rectangular in cross section with doors hinged along their front or leading vertical edges so that their rear vertical edges project outwardly when their doors are open. This type of door has proven to be very dangerous and troublesome in the modern driving environment. For example, the structural integrity of such doors is limited and they may open on impact when the vehicle is in an accident, thus placing the occupants of the vehicle and other persons in danger. Even during normal use, when a conventional door is opened carelessly, the safety of occupants of other passing vehicles, motorcyclists and bicyclists is jeopardized. Furthermore, vehicles having these doors must be parked at a substantial distance from one another to allow occupants to comfortably enter and exit from their vehicles, and to protect neighboring vehicles from dents, scratches or other types of damage.
Presently, designers in the automotive industry are modifying the conventional rectangular-shaped vehicle with outwardly opening doors in favor of aerodynamically designed vehicles. These new vehicles have rounded sides and have cross sections that resemble aircraft fuselages. Efforts to modernize door assemblies to complement the new shapes have assumed a variety of forms, such as the Bertone doors which slide forward, the "gull wing" doors pioneered by Mercedes and used on the Delorean which rotate outwardly about the door's top edge and the unusual doors of the Lamborghini Countach which pivot vertically about the top forward edge of the door. These doors, however, only exist in show cars and certain limited production sports cars.
Vertically slidable vehicle doors for motor vehicles wherein the cross-section of the body is in the form of a curve with the doors slidable up to the top part of the body when the doors are to be opened have been suggested, for example, in expired U.S. Pat. No. 2,819,114 to Lawrence Lake. In the Lake patent, while the vehicle body is constructed with a curved upper part and has doors which are similarly curved, they are required to overlap each other when in the open position so as to facilitate entry and discharge of passengers. The requisite substantial vertical extent intended to fill the vertical extent of door opening when closed and yet permit entry and exit from the vehicle places a substantial structural constraint on the vehicle body design. For example, the doors must move upwardly into the roof section in contrast to downwardly in some location under the vehicle to avoid an inordinately high interior floor arrangement. Further, the vehicle roof must be of a curvature generally conforming to and an extension of that of the exterior side walls restricting the vehicle body to a substantially tubular configuration. The requisite overlapping relation of the doors and related track structure occupies an inordinately large overhead cavity within the overhead vehicle body or roof, weakening its structural integrity, significantly reducing and restricting headroom within the vehicle and at the same time necessitating an exterior vehicle height substantially greater than the vehicle door opening.
In light of the problems with the conventional outwardly opening door and the new aerodynamic designs of vehicles, it is an object of the present invention to provide an improved closure assembly to be used on vehicles which will provide an inexpensive, safe, and trouble-free means for entry and exit from a vehicle which is compatible with the designs of the new vehicles and yet overcomes the limitations of earlier proposals.